Adjustable wrench for nuts



April 21, 1942. F. MALAGRINO ADJUSTABLE WRENCH FOR ,NUTS

Filed Nov. 10, '1939 Patented A... 21, 1942 UNITED STATES 7 PATENTOFFICE 2,2so,s94 ADJUSTABLE WRENCH roa NUTS Francesco Malagrino, Milan,Italy, assignor to Morini & 'Rossi, di Morini, Amadori & 0., Milan,

Italy, a flrm Application November 10, 1939, Serial No. 303,881 In ItalyNovember 10, 1938 2 Claims.

with a toothed portion of the movable jaw.

This toothed wheel is rigidly fixed onto, or is made in one piece with,a disc bearing a scale.

Thus, by moving the disc, the movable law is quickly moved and itsposition may be read on said disc.

The locking of the movable jaw is effected by means of engagement offine teeth on said mov-. able jaw with cooperating teeth on a lockingplate, which latter may be operated by an eccentric lever. Y

According to the invention, the means for moving said disc and toactuate said locking plate are arranged in such a manner that both ofthem maybe easily operated by the thumb of the hand which holds thetool.

According to another feature of the invention, the engaging teethserving to lock the movable jaw combined with the calibration of thescale disc in such a manner that when the movable jaw has been adjustedfor a certain measure reading on the scale, it may then be exactlylocked in this position. This is also facilitated by the use of fineteeth or grooving.

.The annexed drawing shows, by way of example, a wrench constructedaccording to this invention.

Figure 1 is a plan view of the wrench.

Figure 2 is a longitudinal sectional view takenalong the line 22 ofFigure 1;

Figure 3 is a transverse sectional view taken along the line 33 ofFigure 1;

Figures 4 and 5 represents the locking plate andthe locking lever.

Figures 6 and '7 show the movable ja The handle or shank l of thespanner is made from one piece with the fixed jaw 2 has a' hollowportion 3, in the interest of reduction of weight, and a guide 4 onwhich the movable jaw 5 can run with its running part 6. The

running part 6 has a toothed portion or rack I. and a finetoothed ormilled portion.

The locking plate 9 1s assembled in a hollow of the head of the spannerand can ,run lengthwise and has a milled. portion; or grooving, l0,

projecting out from a window on the aforesaid II in the direction of thearrow marked C in tion integral therewith, a movable jaw, meansformountin"g said movable jaw for reciprocal head in correspondence withthe side of the movable jaw carrying the grooving 8. This plate 9 can bemade to gear in the toothing 8 of the running part 6 of the movable jaw,when it ispushed towards the latter.

This movement is carried out by a small lever ll pivoted in I2 andprovided with an eccentric or cam l3 acting against the borders of ahollow ll in plate 9. I

Rack I engages with a gear wheel or pinion l5 secured on agraduated orcalibrated disc l6 pivoted in II, which can be easily turned with thethumb of the same hand which holds the tool. The division of disc I6allows the value of the opening of the jaws to be read. The

movement of the movable jaw is therefor operated with the thumb actingon disc IS.

The arrangement of the operation means It and I6 allow the wrench to beused with the greatest ease by one hand alone in the manner of anordinary fixed fork wrench- In operation, the setting of the relativespacing of jaws 2 and 5 is accomplished by first swinging lever i l inthe direction of the arrow marked A, see Figure 1. This causes theportion of cam I3 of small radius to move toward milled portion l0 thuslessening the distance between the axis of the cam and such milledportion. Naturally, this action causes plate 9 to be retracted in adirection away from the jaws of'the wrench. The pin about which pinionI5 is piv- I oted is. accommodated in an elongated slot which may beseen near the topof the plate 9 as it is shown in Figure 4. The slotelongation is sufficient to accommodate the necessary relative movementbetween plate 9 and the pin constituting the axis of said pinion. Oncethe milled area I0 is out of engagement with milled area 8, the jaws ofthe wrench may be moved by operation of pinion l5 through the handle onits integral disc l6. This effects the major adjustment and theadjustment is maintained by moving lever Figure 1 which causes plate 9to bemoved in the direction of the jaws of the wrench, thereby resultingin the meshing of teeth III with teeth 8. It is evident that theoperations ,just described can be performed with one hand.

What I claim is:

1. An adjustable wrench having a mouth opening substantially in thedirection of the axis of its handle comprising, a fixed jaw, a shankpormovement with respect-to said fixedjaw. said movable jaw including amilled surface and a rack disposed side by side on one surface thereof,

a pinion on said shank in engagement with said for moving saidlast-named means to,and from looking position, the number of teeth perunit 10 length of the milled areas being substantially in excess of thenumber of teeth in a corresponding unit of length of the rack.

2. A wrench according to claim 1 in which a graduated disc is associatedwith the pinion and in which the graduations are spaced apart a distancecorresponding to the space between adjacent teeth of the milled areas.

FRANCESCO MALAGRINO.

